Internal-combustion engine



Feb, l0, 1925.

C. E. SARGENT INTERNAL coMBUsTIoN ENGINE 4 Sheets-Sheet l Filed April 18, 1921 WWU Feb. 10, 1925. 1,525,956

c. E. sARGgN-r INTERNAL GOMBUSTION ENGINE Filed April 18, 1921 `4 vSheets-Sheet 2 lh l hl FMH NB u N. N- a m 31 m ,ff/

Il Il] um f l N5 m g Il l l i N l l N 4 1 z l I Il l :@@k Q Il i l x l i c. E. SARGENT INTERNAL coNBusTroN ENGINE Feb, 1o, 1925. 1,525,956

Filed April 18, -1921 4 Sheets-Sheet 5 Feb 1'0, 1925.

1,525,956 C. E. SARGENT INTERNAL COMUSTION ENGINE AFiled April 18, 1921 4 Sheets-Sheet 4 Ill Patented Feb. L), i925.

PATNT FFICE.

INTERNAL-COMBUSTION ENGINE.

Application led April 18, 1921. ASerial No. 462,254.

T 0 all whom it may concern.'

Be it known that I, CHARLES E. SARenN'r, a citizen of the United States, residing at 2020 Delaware Street, Indianapolis, in the county of Marion and Statel of indiana, have invented ka new and useful lmprovement in Internal-Combustion Engines, ot which the following a specification.

'lhis invention relates to internal combustion engines and particularly oi the yautomotive type.

The primary object of this invention is to increase the thermal etliciei'icy ot' automotive engines at all loads, but particularly at light loads at which automobiles are operating 901/2 of the time.

This invention secures the increased efficiency by providing means for expanding the working medium to practically atmospheric pressure at all loads and lor decreasing the fuel content andincreasing the compression as the load decreases.

Herctoore it has been 'customary in engines ot the automotive t-ype to operate with maximum compression at full load, and to release the gases during the working stroke before the piston has reached the point where compression began, and to throttle the mixture, thereby reducing the compression and efficiency, as the load becomes less.

The result of the present system or cycle is that about 40% of the heat is rejected to the exhaust at full load, and the cciency is rapidly lowered with less than full load wherel automobiles are normally operated as the compression becomes less and the Wire-drawing and back pressure which acts as a brake, increases.

The Sargent cycle used in this invention, so-called to distinguish it from the Otto cycle upon which all automobile engines operate, provides for increasing the compression and decreasing thc fuel as the load gets lighter and conversely increasing the' fuel and decreasing the compression as the load gets heavier and for expanding the working charge to practically atmospheric pressure at all loads.y

Referring now to thedrawings;

Fig. 1 is a partial side elevation of an automotive engine embodying the invention;

Fig. 2 is a partial top plan vievvwith the cover removed showing the valve operating mechanism;

Fig. 3 is a partial section on the broken line 3-3 of Fig. 2;

Fig. 4 is a. partial plan View of the mechanism for operating the inlet cam shaft;

Fig. 5 is a vertical section on the line 5 ot Fig. 4;

Fig. 6 is a vertical section through the carbureter on line 6 of Fig. 7;

Fig. 7 is a horizontal section on the line 7 of Fig. 8;'

Fig. 8 is a verticalsection on the line 8 of Fig. 7; and

Fig. 9 are indicator' diagrams at full and light loads. y

In the embodiment shown in Fig. 1 the block 10 comprises iour cylinders cast in-y tegral to which is secured a. cylinder head 11 which is common to all cylinders by means of bolts 12. Inlet ports 13 are formed upon one side of the cylinder hea-d and communicate with the cylinders 10a While eX- haust ports 14 as shown in dotted lines in Fig. 3 are formed in the opposite side of the cylinder head.

Each of the inlet ports terminates in a tapered seat 15 having a cylindrical seat 16 above it. These seats are covered by inlet valves 17 having corresponding tapered and cylindrical faces, the purpose of which as will later be explained is to give a quick opening and closing of the valves and to prevent wire drawing ol' the charge. These valves slide in guides 18 in the head and are normally held on their seats by means of springs 19. Similar exhaust valves (not shown) in detail are similarly mounted in the head.

The inlet valves are operated by individual bell cranks 20 hingedly mounted at 21 and having rollers 22 journalled o-n the lower end thereof, each ot which engages a cam 23 on the cam shaft 24. This cam shaft is journallcd in suitable bearings in the cylinde-r head and is driven by suitable gearing from the engine crank shaft (not shown) and at one halt' its speed, as this is a four cycle engine. In the same way the 'exhaust valves are operated by means ot' bell cranks 25 and cams 26 on the exhaust cam sha-tt 27. The inlet cam shaft 24 is movable cndwise to vary the time of closing of the inlet valve which varies the compression as will later be explained.

The inlet manifold 28 connects' cach of the inlet passages 13 with the carburetor 29 iutings 31.

cylinder 33 and carries a metering pin 3G which is slidable in the tube 37. This tube is integral with and carried by casting 32.

When the engine is not in'operation the pin 36 serves to close the passage 39 which leads to a gravity feed fuel tank (not shown). `A tapered groove 40 is formed in y the side of the pin 36, which is much larger at the bottom than at the top and communicates With the space at the bottom of the 1 pin 36. An annular groove 41 is formed Within the tube 37 at about the height lof the upper end of the groove 40 when the piston35 is at the bottom of its travel. A series of radial passages 42 connect this groove with the vertical nozzles 43, the lat-V ter terminating in the bottom of the rectangular shaped passages 44 in the side of the cylinder 33. Openings 45 in the`bottom of the casting 32 permit air to pass up from the tube 38, over the nozzles 43 and in through the mixing. chamber 30.

A sleeve 46 is rotatably mounted upon the sleeve 33 which has a. series of openings 47 which are substantially the saine size and shape as the openings 44 and adapted to register therewith. A screw 48 passes through the slot 49 in the side of the carbureter casting 29 and is secured to the sleeve 46. The head of this screw contains a socket in which is pi-votally mounted a `rounded end of a link 50, the opposite ends of the link being similarly mounted in the short arm of a bell crank 51 which is pivotally mounted at 52. y

It Will be understood from the foregoing lthat as the bell crank is moved the sleeve 46 will be lrotated upon the cylinder 33 thereby artially covering and uncovering the openings 44 therein. The longer arm 53 of the bell crank is connected bymeans of a link- 54 with the lever arm 55 which is carried by a shaft 56 which is journalled in the side of the head l1 as shown in Fig. 5. The lever 55 is operably connected to the lever 57 which is controlled by the operator through the rod 58. This rod may be connected either through a foot accelerator or through a hand controlled lever. v

A lever 56a is keyed on the inner end of this shaft 56 and carries a pin 59 on which is journalled a roller G0 which lies between the flanges 61 on't-he intake cam shaft 24. Thusit -Willbe understood that as the lever 57 is movjed back and forth the inlet earn A lpiston 35 is slidably mounted Within the the point of closing of the inletl valve and thus increasing the compression in the cylinder as the cam shaft 24 is moved to the left and decreasingvthe compression as the cam shaft is moved to the right.. The advance face of the cam is preferably made straight and hence the time of opening in the inlet valve will remain substantially the same in all cases. Referring now to Fig. 3, it Will be observed that by the use of the piston extension on the poppet valve, a quick opening and closiirg is obtained, as the valve is moving'rapidly except When close to the seat, while the final seating of the valvemay take place relatively slowly. Thus, a valve is provided which is quick opening andclosing and at the same time is relatively noiseless.

Referring now to Figs. 6, 7k and 8, the slight. rarefaction in the intake manifold 28 transmitted through thev hole 34a will cause the piston 35, as shown in Fig. 8, to rise uncovering the inner side of the openings 44. The space over the top of the piston 35 communicates with the intake manifold through a. small opening 342l so that the piston 35 will not have a tendencyto flutter With all the minor fluctuations of pressure in the intake manifold. As the suctionv increases the piston 35 will be raised 4uncovering a -7 greater area of the opening 44, and at the same time, raising the pin '36 so that a larger part of the groove 40 Will be brought over the annular groove 41 and consequently a greater amount of fuel will be fed to the nozzles 43.

As the cam shaft 24 is moved to'the left to give increased compression, the sleeve 46 is simultaneously turned in a clockwise direction as shown in Fig. 7 lbringing the openings 47 more 4nearly into registration with the openings 44.

The air 4iS thus adfili mitted more rapidly into the intake pas- 1 sage and the vacuum drops somewhat, causing the piston 35 'to-fall.. The piston car-- ries the metering pin with -itthereby defuel to the nozzles 43. It will thus be seen that the volume of air admitted to the cyl-- inderis increased as the inlet valve is held open longer by the large end of the cam 23 and that at the same time the amount of yfuel fed is decreased. I n other words, the port. widens and to maintain the same equilibrium or pressure ratio between the air in the manifold and outside theI manifold constant, the piston 35 will drop reducing the fuel supply though the airfvelocity (a constant in this forni ot' cai'bu'reter) will be the same. 'lhis ,velocity is approximately constant because the difference in pressure on the two sides ot' the opening.

44 is nearly constant while the engine is running, being balanced by'the constant Lasagne and air a whirling motion as it enters they.

chamber 30. The spiral flutings 3l are formed in the side walls to increafe this action.v The hot air passage (5i-l is formed about this mixing chamber and exhaust gases are led thereto through the pipe 64, which heat the tinted walls and pass out to the atmosphere through the opening 65.

. 'lhe centrifugal force developed throws the ungasilied fuel on this hot .surface where it `becomes gasilied and passes into the air current while the' air absorbs very little heat as it only touches the top of the plates.

it butterfly valve G6 is placed in the passage 65 and connected by means ofy a rod 67 with the bell crank 63 so that as the amount of fuel fed is decrease-d, the valve 66 will be v closed, thereby decreasing the Flow of exhaust gases to the heating chamber 63.

If we turn now to the indicator diagram as shown in Fig. 9 and assume that the piston is at the top of its stroke which correspends to the position A on the diagram, and that the cam shaft is set for extreme no load position, the line A Bfwill represent will represent the rise in pressure due to ignition, the line D B is the working stroke and B A which is substantially the same as the line A B is the exhaust stroke.

If, however, on the intake stroke we cut olf attivo thirds stroke the intake line will then be A E I", F G will'be the compression line, G ll the rise due to ignition, H B the expansion line and B A the exlhanst line as before.

Instead of closing the admission valve and cutting olf at approximately two thirds the suction stroke at full load, substantially the same resultlmay be obtained by permitl ting the inlet valve to remain open during approximately one third of the compression stroke. In that case the inlet valve would close at E; on the return or compression stroke instead of at E on the outward or suction stroke as before. The compression line E G, the ignition line G I-I and the n expansion line Il B would remain substanlially the ksaine as before. In a niultlple 'cylinder engine the charge forced out of one cylinderv for this 1A, stroke is drawn into another so that there is very little regurgitation through the carbureter.

In order to increase the compression for lightl loads when closing the admission valve' at approximately one third the compression stroke. the inlet cam must be so beveled that 'be understood that it is capable of many more modifications. Changes, therefore, in the construction .and arrangement may be made without departing froi'n the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention` to claim all novelty inherent in my invention as broadly as possible in view of the prlor art. i

What I claim as new' and desire to secure by Letters Patent is:

l. In an internal combustion engine, a cylinder, a. piston therein, an inlet valve and an exhaust valve in said cylinder, means for varying the time said inlet valve is open whereby the compression in said cylinder is varied, a carbureter and means operably connected to said first-mentioned means foi decreasing the fuel content of the mixture as the compression is increasedand for increasing the fuel content of the mixture as the compression is decreased.

2. In an internal combustion engine, a cylinder, a piston therein, an inlet valve and an exhaust valve in-said cylinder, a cam shaft having a cam for operatin said inlet valve, said cam having alongitudinally varying face and means for shifting saidv cam shaft longitudinally for varying the time of closing said inlet valve whereby the compression in said cylinder is varied, a carbureter and means'operably connected to said first mentioned means for decreasing the fuel content. ofthe mixture as the compression is increasediand for increasing the fuel content of the mixture as the compression is decreased.

3. In an internal combustion engine, a cylinder, a piston therein, an inlet valve and an, exhaust valve in said cylinder, a cam shaft having a cam for operating said inlet valve, said cam having a longitudinally varying face and means for vshifting said cam/shaft longitudinally for varying the time said inlet valve is open whereby the compression in said cylinder is varied, 'a c'arbureter having an opening for the passage o'f air, a fuel nozzle adjacent said opening for decreasing the fuel content of the mixture asy the compression is increased and for increasing the fuel content of the niixture as the compression is decreased.

4. In an internal' combustion engine, a cylinder, a piston therein, an inlet valve and an exhaust valve in said cylinder, a cam shaft haringa cam for operating said inletvalve, said cam having a longitudinally varying face and means for shifting said cam shaft longitudinally for varying the time of closing of Said inlet valve whereby the initial pressure in said cylinder is Varied, a carburetor having an opening for the passage of air, fuelfnozzle adjacent said opening, and means operahly connected to said first mentioned means for \\arying said opening for decreasing the fuel content ofthe mixture as the compression is increased and for increasing the fuel content of the mixture as the compression is decreased.

5. In an internal conibustion engine, a cylinder, a piston therein, aninlet valve and an exhaust valve in said cylinder, means for varying the time the inlet valve is; open whereby the compression in said cylinder is varied, a carbureter having a plurality of openings for the passage of air, a fuel nozzle adjacent said openings, and means operably connected to said first-mentioned means for varying said openings for decreasing the fuel content of the mixture as the compression is increased and for increasing the -fuel content of the mixture as the compression is decreased.

6. ln an internal combustion engine, a cylinder, a piston therein, an inlet valve and an exhaust valve in said cylinder, means for varying the time of closing of `said inlet valve whereby the compression in said cylinder is varied, a carbureter having a plurality o'f radial openings for the passage of air, a fuel nozzle adjacent said openings. and Ameans(op-eraloly connected to said firstmentioned means for varying said openings for decreasing the fuel content of the mixture as the compression is increased and for increasing the fuel content of the mixture as the `compression is decreased.

T. In an internal combustion engine, a. cylinder, a piston therein, an inletl valve and an exhaust valve in said cylinder, means for varying the time said inlet valve is open whereby the compression in said cylinder is varied, a carbureter having a mixing chamber, a plurality of radial openings for the passage of air into said mixing chamber, a fuel nozzle adjacent said openings, means operably connected to said first-mentioned means for varying said openings for decreasing the fuel content of the mixture as the compression is increased and for increasing the fuel content of the mixture as the compressionis decreased and means for heating the walls of the mixin` chamber.

.cHARLns E. siiienufr. 

